Pipeline for conveying plastic melt

Abstract

The invention relates to a pipeline for conveying a plastic melt. The pipeline comprises a melt pipe for a plastic melt to pass through and a heat conducting oil pipe sheathed outside the melt pipe, wherein both ends of the melt pipe are provided with connecting flanges; the melt pipe and the heat conducting oil pipe form a jacket for heat conducting oil to pass through; both ends of the heat conducting oil pipe are provided with an oil inlet and an oil outlet which are communicated with the inner cavity of the jacket; the heat conducting oil pipe is further provided with an air exhausting device communicated with the inner cavity of the jacket; the inner cavity of the jacket is internally provided with spiral guide vanes, so that a spiral flow passage is formed in the inner cavity of the jacket; and the oil inlet and the oil outlet are respectively communicated with both ends of the spiral flow passage. The spiral flow passage can ensure that the heat conducting oil flows in the jacket uniformly, the melt temperature inside the melt pipe is stable, production stability can be ensured, product cost can be reduced, and the plastic film quality further can be improved.

Description

technical field [0001] The invention relates to a pipeline for transporting plastic melt on a biaxially stretched plastic film production line. Background technique [0002] The pipeline for transporting plastic melt is very important to the biaxially oriented plastic film production line, especially for ultra-thin plastic films below 5 microns, the temperature fluctuation of the plastic melt needs to be controlled below ±0.5 degrees, otherwise the production line will break the film. At present, there are two heating methods for the plastic melt in the melt pipeline. One is electric heating, and the ceramic heater is close to the outer wall of the melt pipe for heating. This heating method has large temperature fluctuations and the heater is easily damaged. The other is heated by heat-conducting oil, and a cylindrical heat-conducting oil pipe is placed outside the melt pipeline. The annular passage between the heat-conducting oil pipe and the melt pipe forms a jacket, and t...

AI Technical Summary

Problems solved by technology

The other is heated by heat-conducting oil, and a cylindrical heat-conducting oil pipe is placed outside the melt pipeline. The annular passage between the heat-conducting oil pipe and the melt pipe forms a jacket, and the heat-conducting oil flows in the jacket. The sleeve is easy to form a dead zone, and the heat transfer oil flows unevenly inside, resulting in uneven temperature distribution of the melt in the melt pipeline, which easily causes film breakage in the production line and increases production costs

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